Shoe last



GQ'CLAUSING Dec. 29, 1936.

SHOE LAST Filed July 5, 1935 IN V EN TOR.

Gear 9 C/aus/h BY y Y.

A TTORNEY Patented Dec. 29, 1936 PATENT OFFICE SHOE LAST GeorgeClausing, Portsmouth, Ohio, assignor to Vulcan Corporation, Portsmouth,Ohio Application July 5, 1935, Serial No. 29,779

2 Claims.

This invention relates to shoe lasts, and is directed particularly tothe hinge means which joins the toe and heel parts of the last to permitrelative movement of the last parts and a re- 5 sultant expansion andcontraction of-the last as to length.

A shoe last is normally made from a solid block of wood, and this solidblock of wood is later separated into two parts which are commonly knownas fore and back or toe and heel parts, these parts being joinedtogether by a suitable hinge means which permits of the necessarymanipulation of the shoe last in accordance with the present well knownshoe making practice. That is, collapsing and expanding of the last.Thus, the weakest point in the shoe last structure has been at the hingearea where the separate toe and heel parts are joined and where there isa V-shaped cut in the last to permit of a relative rotative movement 20between the last parts, or collapsing and expanding of the last. Whenthe last parts are in expanded position, there is only a small abuttingarea between the toe and heel parts, this abutting area being confinedto a relatively small bearing surface on which one last part rotatesrelative to the other and a small abutting area at the bottom of thelast which acts as a stop to prevent relative movement of the last partspast their normal expanded position.

It has been found that there is a tendency for shoe lasts to break atthe weakest point, the hinge area, during soling or leveling of a shoeon the last. In making a shoe on the last, the last is inverted, theheel end being supported on a jack pin and the toe being supportedadjacent its extreme outer end on some suitable rest. Considerablepressure is exerted on the last throughout its length during these twomentioned operations with a resultant compression force on the last atthe unsupported hinge area which places a tensionstress on the hinge anda compression stress on the small abutting area between the toe and heelparts and adjacent the bottom of the last, the bottom of the last, asreferred to, being uppermost during the process of making a shoe. Suchcompression force tends to pull the last apart at the hinge area and tocrush the abutting surfaces between the toe and heel parts and adjacentthe bottom of the last.

One object of this invention 'is to provide a shoe last which hassubstantially equal resistance to compression and tension stresses atits hinge area as it has throughout its solid remainder. In theaccomplishment of this object, means are 55 provided to preventabnormal-displacement of the toe and heel parts beyond their properrelative positions when the last is expanded, and, at the sametime,means are provided for offsetting the compression and tension forcesexisting at the hinge area during the leveling, soling and other 5- shoemaking operations. r 1

Another object of this invention is to provide a hinge construction forconnecting the toe and heel parts of a shoe last which is of a nature toI permit the axis of rotationormo'vement of the 10 one last partrelative to the other to be located at a minimum distance above thebottom of the last whereby rotation or movement of one last partrelative to the other in collapsing of the last will produce a maximumcontraction or shortenl5 ing of the last. With this invention, thedisposition of the axis of rotation between last parts at an extremelylow point with relation to the bottom of the last is accomplishedwithout lessening the strength of the hinge area.

Variousother objects and advantageous features of thisv invention may behad from the following description, and one embodiment thereof may beseen in the accompanying drawing where similar characters of referencedesignate corresponding parts and wherein:

1.. Fig. 1 is a side elevation of a last embodying the invention withthe part adjacent to the hinge broken away to show the hinge parts inelevation, the last being shown in expanded position.

Fig. 2 is a side elevation of a last with the portion of the lastadjacent to the hinge broken away to show the hinge parts in elevation,the last parts being shown in their collapsed contracted position.

' Fig. 3 is a cross sectional view of a portion of the last at the hingethereof showing the hinge parts in plan view.

Fig. 4 is a detailed view showing a modification of the stop link.Referring to the drawing, a shoe last is shown which includes the usualtoe or fore part I and heel or back part 2 connected together by a hingemeans which will be presently described. It will be understood that theshoe last is ordinarily first made from a solid block of wood and thefore and back parts I and 2 are later separated by a straight and anarcuate cut to separate the fore and back parts and to provide aball-like part 3 and a-socket 3' to form a hinge joint be- 50 tween theparts. As' shown, the back part2 is out away'at its left hand uppercorner to increase the effective circumferential area of the part3 andpermit the back part 2 to rotate or move about an axis at the-center ofthe ball-like part 55 3 relative to the fore part I. Such relativemovement rotation of the parts permits the last parts to be collapsed asshown in Fig. 2 to shorten the last length for removal of the last froma shoe, or permits the last to be expanded and made longer as shown inFig. 1, in which position the last parts are placed for the making of ashoe, the hinge joint being adjacent the last bottom, as .shown, to makethis collapsing and expanding possible.

One usual connection between the fore and heel parts of the last takesthe form of a spring or tension member disposed in a routed out portionin both the fore and back parts and attached at one end to the back partand at its other end to the fore part, such member ordinarily beingunder tension to hold the last two last parts together. The connectionsfor the opposite ends of the spring or tension member are disposedoppositely of the hinge joint including the ball-like portion 3 in theback part and the socket portion in the fore part with the spring ortension member crossing such hinge joint. With this arrangement,considering that the back part moves or rotates relative to the forepart about the center of the hinge joint from one side to the other ofthe axis of rotation of the back part it tends to snap the last into itsexpanded or collapsed position, as the case may be, the spring ortension member being put under greatest tension just as it crosses'theaxis of rotation of the back part.

In addition to the spring or tension member as a connecting meansbetween the fore and back parts of the last, two links were ordinarilyprovided,'one on either side of the spring or tension member andconnected at their opposite ends to the same pins to which the spring ortension member was connected, the connections between the links and the,pins being a sloppy fit so as not to interfere with movement of one lastpart relative to the other about the axis X. The purpose of these linkswas to prevent compression stress on the bottom of the last, or alengthwise force on the last, from separating the fore and back partswhich, without the links, would be connected together solely by thespring or tension member under tension. Such construction of theconnecting means between the fore and back parts of the lastnecessitated that the hinge joint or ball and socket arrangement, or anyother axis of rotation between the fore and back parts of the last, belocated a considerable distance above the bottom of the last to provideabutting surfaces between the fore and back parts and at the bottom ofthe last, which were of sufiicient area to withstand the compressionforce exerted on the bottom of the last during the shoe making operationand at a time when the last was inverted and supported only at oradjacent to its opposite ends. The location of this axis of rotation asubstantial distance above the bottom of the last necessarily reducedthe amount of shortening of the last brought about by rotation of theback part relative to the fore part in collapsing the last. It isdesirable that the axis of rotation of the back part relative to thefore part be as close to the bottom of the last as is possible.

In accordance with this invention, the fore and back parts of the lastare routed out to form chambers 6 in the fore and back partsrespectively, which'chambers are coincident when the last is incollapsed position as shown in Fig. 2. A spring or tension member 4 isdisposed in this chamber with one of its ends connected to a transversepin 5 in the fore part and its opposite end connected to a transversepin 5 in the back part, the spring or tension member 4 being of a shapeand the pins 5 being so located that the spring or tension membercrosses the axis of r0- tation of the back part relative to the forepart during movement of the last parts into collapsed or expandedpositions, and is always under tension so as to hold the last fore andback parts together. Such crossing of the spring or tension memberacross the axis of rotation between the fore and back parts of the lastresults in a snapping ,of the parts into their collapsed or expandedpositions after the spring or tension member crosses the axis ofrotation of the one part relative to the other, which axis is indicatedat X, the spring or tension member being placed under greatest tensionjust as it is crossing such axis of rotation.

As shown, a link 9 is also disposed in the chamber containing the springor tension member 4. However, in place of being disposed on the samepins 5 with the spring or tension member and across the axis X aspreviously practiced, the link 9 is connected at its opposite ends totransverse pins 7 and 8 by means of slots l0 and H, one in the last forepart and the other in the last back part, the pins T and 8 and the linkcarried thereby being disposed a substantial distance above the pins 5of the spring or tension member 4 and the axis X. As shown in Fig. 3,two links 9 are used, these links being separated by spacers l3,although only one link may be used.

During the making of a shoe on a last'oi the type shown, the last isturned up-side down from the position shown in Fig. 1 of the drawing andis supported at one end by means of a jack pin disposed in the hole 20provided therefor and at the other end on a suitable support on whichthe toe end rests adjacent its extreme end. With the last in thisposition, the shoe upper having been placed on the last, what is knownas the soling and sole leveling operation takes place. During these twooperations, considerable pressure is exerted on the bottom of the lastat various points between the two supports, one at each end of the last.Such pressure tends to spread the last at the hinge connection betweenthe fore and back parts, with the greatest compression being exerted atthe abutting surfaces l6 and I1 beneath the hinge joint and at the lastbottom. It also places a considerable tension stress on the spring 4 andwould tend to separate the last fore and back parts were it not for thelinks 9 which, as hereinbefore stated, were previously disposed on thesame pins 5 as the spring 4 and thus in substantially the same plane.

As will be noted in the drawing, the link or links 8, in accordance withthis invention, are disposed a substantial distance above the pins 5 inthe spring 4, and also above the hinge joint formed by the ball portion3 and depression 3 with contacting surfaces I4 and I5. With the link orlinks 9 so located, any compression force on the last bottom and whichtends to separate the last at its top and crush the last at the abuttingsurfaces 16 and I1 will be compensated for by the link or links 9preventing the last from spreading at its top. At the same time, thelever arm, as represented by an imaginary line drawn from each of thepins I and 8 to the abutting surfaces 16 and I! at the bottom of thelast, are so lengthened that it would take considerably more pressurethan that exerted on the bottom of the last during the soling and soleleveling operations to crush the last at or near these abuttingsurfaces. Thus, it is possible to reduce the area of these abuttingsurfaces and lower the hinge joint between the last parts more closelyto the last bottom.

The possibility of lowering the hinge joint between the last parts at apoint closely adjacent the last bottom is highly desirable in thatrelative rotation of the last parts to a collapsing position as shown inFig. 2 will result in a quicker and at the same time a greatershortening of the last length whereby the last may be collapsed andwithdrawn from the shoe without danger of stretching or mutilating theshoe which has been built on the last.

In operation, the fore and back parts of the last are normally in theposition shown in Fig. 1. That is, the last is expanded to the positionwherein it has the greatest length and a shoe is constructed on the lastwhile the parts are in this position. It will be noted that the pins 1and 8 are bearing against the outer extremities of the elongated slotsH] and l I. In other Words, the pins 1 and 8 are bearing against thepoints l2 of the slots 10 and H. Thus, it will be seen that the tendencyof any pressure exerted on the bottom of the last and which tends tospread the last at its top while such last is supported adjacent itsopposite ends will be resisted by the link or links 9. When the last iscollapsed as shown in Fig. 2, the pins 1 and 3 move to the innerextremities of the elongated slots I0 and II. Thus, a connection isprovided between the fore and back parts of the last which, while notinterfering in any way with the usual collapsing and expanding movementsof the last, is much stronger than any heretofore employed and which isefiective to prevent crushing of the abutting surfaces at the bottom ofthe last when pressure is exerted thereon. Referring to Fig. 4 of thedrawing, I have shown the modified form of link 9 wherein the opening I8is just sufficiently large to fit snugly on the pin 8 while the opening[9 which fits on the pin 1 takes the form of an elongated slot.

Having thus described the invention, I claim:

1. A shoe last comprising a fore part, a heel part, a hinge between saidparts to permit expansion and contraction of the last, a spring memberat said hinge tensioned to produce compression at the joint of saidhinge and operable to snap said fore and heel parts into theircontracted and expanded relative positions, a pair of pins rigidlysecured respectively in the heel and fore parts of the last asubstantial distance above the axis of said hinge, a rigid stop linkhaving apertures in its ends within which the pins are received saidapertures permitting shortening of the last and being so spaced apartwith respect to the pins as to limit the rotation of the hinge beyondits normal position when the last is expanded.

2. A shoe last comprising a fore part, a heel part, a hinge between saidparts to permit contraction and expansion of the last, a chamber withinthe body of the last, a spring member within said chamber tensioned toproduce com pression at the joint of said hinge and operable to snap thesaid fore and heel parts relatively into their contracted and expandedpositions, a pair of pins rigidly secured respectively in said fore andheel parts a substantial distance above the axis of said hinge, a pairof rigid stop links situated in said chamber having apertures in theirends within which said pins are received said apertures permittingshortening of the last and so spaced apart with respect to the pins asto limit the rotation of said hinge beyond normal position when the lastis expanded.

GEORGE CLAUSING.

